It is conventionally well-known that a water-soluble rhodium salt is used to obtain a contrast-increased photographic emulsion.
However, the water-soluble rhodium salt-used silver halide photographic light-sensitive material, although capable of forming a high-contrast image, has the disadvantage that it is liable to get increasingly fogged and to get its contrast reduced during its raw-stock storage.
As techniques to improve the raw-stock storage stability of a photographic light-sensitive material there are many techniques such as the use of cadmium compounds disclosed in U.S. Pat. No. 488,709, the use of nucleic acid-decomposed products disclosed in JP O.P.I. Nos. 23618/1950, the use of quinones or 3-pyrazolidones disclosed in JP O.P.I. Nos. 23383/1969, 11029/1977 and 154247/1985.
However, these conventional techniques are effective for low-speed silver chloride or silver chlorobromide emulsions, but, when applied to a high-speed silver iodobromide emulsion containing an appropriate amount of silver iodide, can not be deemed effective enough to prevent the emulsion from fogging and from contrast reduction during its storage, and in addition, have the problem that they are inferior in the safety to safelight that is essential for the safe handling of photographic films particularly in the darkroom, and thus a further improvement of them has been called for.